Hyperbolic Meta-Antennas Enable Full Control of Scattering and Absorption of Light
| Autor: | Antonietta Parracino, Nicolò Maccaferri, Yingqi Zhao, Giuseppe Strangi, Francesco De Angelis, Marzia Iarossi, Tommi Isoniemi |
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| Rok vydání: | 2019 |
| Předmět: |
Physics
Scattering Mechanical Engineering Bioengineering 02 engineering and technology General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Light scattering Computational physics Dipole Excited state Radiative transfer General Materials Science Direct coupling 0210 nano-technology Absorption (electromagnetic radiation) Magnetic dipole |
| Zdroj: | Nano Letters. 19:1851-1859 |
| ISSN: | 1530-6992 1530-6984 |
| Popis: | We introduce a novel concept of hybrid metal-dielectric meta-antenna supporting type II hyperbolic dispersion, which enables full control of absorption and scattering of light in the visible/near-infrared spectral range. This ability lies in the different nature of the localized hyperbolic Bloch-like modes excited within the meta-antenna. The experimental evidence is corroborated by a comprehensive theoretical study. In particular, we demonstrate that two main modes, one radiative and one non-radiative, can be excited by direct coupling with the free-space radiation. We show that the scattering is the dominating electromagnetic decay channel, when an electric dipolar mode is induced in the system, whereas a strong absorption process occurs when a magnetic dipole is excited. Also, by varying the geometry of the system, the relative ratio of scattering and absorption, as well as their relative enhancement and/or quenching, can be tuned at will over a broad spectral range, thus enabling full control of the two channels. Importantly, both radiative and nonradiative modes supported by our architecture can be excited directly with far-field radiation. This is observed to occur even when the radiative channels (scattering) are almost totally suppressed, thereby making the proposed architecture suitable for practical applications. Finally, the hyperbolic meta-antennas possess both angular and polarization independent structural integrity, unlocking promising applications as hybrid meta-surfaces or as solvable nanostructures. |
| Databáze: | OpenAIRE |
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